Theresa May has said she is ready to make way for a new Conservative leader and Prime Minister to take Britain through the second phase of Brexit negotiations.
But how could that happen?
– Thursday March 28 or Friday March 29
Mrs May is expected to bring her Withdrawal Agreement back to the House of Commons for a third “meaningful vote”.
If it passes, this automatically triggers an extension to the Brexit process to May 22, when the UK would leave with a deal.
The EU has said it is ready to start negotiating a future trade and security relationship as soon as the Withdrawal Agreement and Political Declaration have been ratified in Westminster, so the second phase of talks could be said to start as soon as MPs approve the deal, making an immediate resignation possible.
– Monday April 1
MPs will debate their favoured Brexit options in a second round of “indicative votes” in the Commons. If the deal has been passed, this cannot affect the Withdrawal Agreement, but it could exert a powerful influence on the kind of future relationship pursued by Mrs May’s successor.
– Friday April 12
If Mrs May’s deal has not passed, the UK must seek a further extension to negotiations or leave without a deal. If there is no Withdrawal Agreement, talks are nonetheless likely to start soon on a trade and security deal between what will remain important partners and close neighbours.
Once the Withdrawal Agreement is passed, the Government needs to rush an implementation bill through Parliament, along with other legislation needed to ensure a smooth departure. It is unclear whether Mrs May would delay her resignation until this process is complete and the UK formally leaves on May 22.
It would be possible for her to declare she is stepping down, but to remain in post during the contest to select a successor.
If she remains in office until May 25, she will overtake Gordon Brown’s tenure of two years and 319 days in office to become the 35th longest-serving PM in British history. If she lasts until May 26, she outstrips the Duke of Wellington and another 28 days to June 23 will take her past Neville Chamberlain.
The process of picking a new leader requires Conservative MPs to whittle down contenders to a shortlist of two, who then go forward to a final vote by members in the country.
Precise rules for the contest are a matter for the 1922 Committee executive, led by chairman Sir Graham Brady.
A wide field of candidates is expected, with Boris Johnson, Michael Gove, Jeremy Hunt, Sajid Javid, Amber Rudd and Dominic Raab among those thought to be mulling their prospects.
Candidates who secure the required nominations would be subjected to a series of secret ballots of MPs, with one eliminated on each round until only two remain. This process could be completed within a fortnight or so of the contest being declared.
The next stage would be expected to take around six weeks, as the remaining two contenders campaign for support in a postal ballot involving around 125,000 members around the country.
If Mrs May were to pass her Withdrawal Agreement by the end of this week and declare her resignation immediately afterwards, a new leader could therefore be in place as early as the first week of June. If she delayed until the formal date of Brexit on May 22, the process could be completed in mid-July.
She is due to represent the UK at the annual G20 summit in Osaka, Japan, on June 28-29, which could be her last outing on the international stage before stepping down.